This study will estimate the current direct and indirect costs of Alzheimer's disease to the nation. These estimates will be based on longitudinal data on the utilization and costs of medical, social and informal services for institutionalized and non- institutionalized Alzheimer's disease patients. Specifically, this study proposes to collect, analyze and estimate: 1) formal medical and health care expenditures (i.e., expenses for physician services, laboratory tests and other diagnostic procedures, drugs and prescriptions, home health care, other medical personnel, hospital and nursing home care, etc.); 2) formal social service expenditures (i.e., senior center services, adult day care, nutrition programs, transportation services, etc.); 3) informal care provided by family members and caregivers (i.e., assistance with household chores, mobility and the basic activities of daily living); and 4) societal costs (e.g., productivity losses of both victims and caregivers). In general, we expect that the greater the level of disease severity and the greater the degree of formal care, the higher the costs of care. We will thus be studying the differences in cost of care for mild, moderate and severely impaired Alzheimer's patients in non-institutionalized and institutionalized settings. To estimate these costs, data will be obtained prospectively for a period of one year from a minimum of: 1) 100 non- institutionalized Alzheimer's disease patients; 2) 100 caregivers of the non-institutionalized patients sample; 3) 100 institutionalized Alzheimer's disease patients; and 4) 150 caregivers of the institutionalized patient sample. Non- institutionalized Alzheimer's disease patients will be selected from the patient population of two State of California Alzheimer's Disease Diagnostic and Treatment Centers, while the institutionalized patient population will be selected from a group of Alzheimer's disease patients residing in 14 skilled nursing facilities.